In an overpopulated world where all signs of nature have been obliterated and a wall has been erected to keep out plague-ridden animals, twelve-year-old Mika refuses to believe that his twin sister was killed after being abducted, and continues to search for her in spite of the dangers he faces in doing so. Interest Level: 5-8 Reading Level: 6.0 ATOS Book Level: 6 AR Interest Level: MG AR Points: 18 AR Quiz: 129388EN Reading Counts Level: 6.3 Reading Counts Points: 25 Lexile Measure: 910 Iowa Teen Award 2013 - 14.